Call: sma(formula = longev ~ lma * rain, data = low_soilp, log = "xy",
slope.test = 1)
Fit using Standardized Major Axis
These variables were log-transformed before fitting: xy
Confidence intervals (CI) are at 95%
------------------------------------------------------------
Results of comparing lines among groups.
H0 : slopes are equal.
Likelihood ratio statistic : 2.367 with 1 degrees of freedom
P-value : 0.12395
------------------------------------------------------------
H0 : common slope not different from 1
Likelihood ratio statistic = 8.677 with 2 degrees of freedom under H0
P-value : 0.013057
Coefficients by group in variable "rain"
Group: high
elevation slope
estimate -2.321737 1.1768878
lower limit -3.475559 0.7631512
upper limit -1.167915 1.8149286
H0 : variables uncorrelated.
R-squared : 0.3407371
P-value : 0.013891
H0 : slope not different from 1
Test statistic: r= 0.1975 with 15 degrees of freedom under H0
P-value : 0.44733
Group: low
elevation slope
estimate -3.837710 1.786551
lower limit -5.291926 1.257257
upper limit -2.383495 2.538672
H0 : variables uncorrelated.
R-squared : 0.80651
P-value : 0.00041709
H0 : slope not different from 1
Test statistic: r= 0.8126 with 8 degrees of freedom under H0
P-value : 0.0042704
Code
# 结论: H0 : slope not different from 1 ,p 为 0.004,拒绝 h0# 检查共同截距 -------------------------------------------------------------low_soilp_elev <-sma(longev~lma+rain, log="xy", type ="elevation", data=low_soilp)summary(low_soilp_elev)
Call: sma(formula = longev ~ lma + rain, data = low_soilp, log = "xy",
type = "elevation")
Fit using Standardized Major Axis
These variables were log-transformed before fitting: xy
Confidence intervals (CI) are at 95%
------------------------------------------------------------
Results of comparing lines among groups.
H0 : slopes are equal.
Likelihood ratio statistic : 2.367 with 1 degrees of freedom
P-value : 0.12395
------------------------------------------------------------
H0 : no difference in elevation.
Wald statistic: 6.566 with 1 degrees of freedom
P-value : 0.010393
------------------------------------------------------------
Coefficients by group in variable "rain"
Group: high
elevation slope
estimate -3.140896 1.551400
lower limit -4.079825 1.109374
upper limit -2.201966 2.011726
H0 : variables uncorrelated.
R-squared : 0.3407371
P-value : 0.013891
Group: low
elevation slope
estimate -3.304865 1.551400
lower limit -4.353328 1.109374
upper limit -2.256403 2.011726
H0 : variables uncorrelated.
R-squared : 0.80651
P-value : 0.00041709
Code
plot(low_soilp_elev)
Figure 25.5: 共同截距差异显著的图形
结论: H0 : no difference in elevation. p 为 0.01 共同截距有显著差异
Call: sma(formula = longev ~ lma + rain, data = low_soilp, log = "xy",
type = "shift")
Fit using Standardized Major Axis
These variables were log-transformed before fitting: xy
Confidence intervals (CI) are at 95%
------------------------------------------------------------
Results of comparing lines among groups.
H0 : slopes are equal.
Likelihood ratio statistic : 2.367 with 1 degrees of freedom
P-value : 0.12395
------------------------------------------------------------
H0 : no shift along common axis.
Wald statistic: 0.2091 with 1 degrees of freedom
P-value : 0.64745
------------------------------------------------------------
Coefficients by group in variable "rain"
Group: high
elevation slope
estimate -3.140896 1.551400
lower limit -3.475559 1.109374
upper limit -1.167915 2.011726
H0 : variables uncorrelated.
R-squared : 0.3407371
P-value : 0.013891
Group: low
elevation slope
estimate -3.304865 1.551400
lower limit -5.291926 1.109374
upper limit -2.383495 2.011726
H0 : variables uncorrelated.
R-squared : 0.80651
P-value : 0.00041709
结论: H0 : no shift along common axis. p 为 0.64,接受 h0,无延主轴方向的漂移。
Warton, David I, Remko A Duursma, Daniel S Falster, and Sara Taskinen. 2012. “Smatr 3– an r Package for Estimation and Inference about Allometric Lines.”Methods in Ecology and Evolution 3 (2): 257–59.
Warton, David I, Ian J Wright, Daniel S Falster, and Mark Westoby. 2006. “Bivariate Line‐fitting Methods for Allometry.”Biological Reviews 81 (2): 259–91.